First, let's deal with the "Kahr girls." Most likely, they are the best-looking girl in the office staff or somebody's girlfriend. This is very common, especially in low-budget advertising. BTW: If you ever want to see girls unappealing enough to turn you gay, check out the high-buck fashion ads in Harper's Bazaar sometime.
Second, Flo is perky, cute and has a great smile but I can't imagine her as a sex object. Somebody's sister, maybe. Or the nice girl next door who bakes cookies. Besides, she's really 40 years old and married (True!).
Third, sex in advertising works well enough that it has survived more than a century of so-called moral outrage. The gorgeous girl or handsome guy (they work well, too. Remember the Marlboro Man or Tom Selleck in the NRA promotions?) get your attention, hopefully long enough for you to find out what the ad is promoting. The mistake is in the saying "sex sells." It does nothing of the sort. You might be bedazzled by the beautiful blonde but, unless you're about 12, you know darn well she doesn't come with the product. If the product can't be sold on its own merits, it's not going to sell, even if the girl in the ad is naked and holding a sign with her phone number.
Incidentally, there's no guilt in pausing for an ad with a hottie as you thumb through a magazine or catalog. It's not pornography, it's not adultery and your views on sex and the sanctity of marriage don't matter. The response is hard-wired into your brain; if you still have a pulse, you'll respond. Male or female, humans associate physical beauty with superior reproductive capabilities. That's how nature works. And then you turn the page and read on...